NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC.

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

Vindicator Lidar Assessment 

for Wind Turbine Feed-Forward 

Control Applications

Cooperative Research and Development 

Final Report

CRADA Number: CRD-09-352

NREL Technical Contact: Dr. Alan Wright

CRADA Report

NREL/TP-5000-61078

January 2014
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of 

any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately 

owned rights. Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors 

expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

This report is available at no cost from the National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Available electronically at http://www.osti.gov/bridge

Available for a processing fee to U.S. Department of Energy

and its contractors, in paper, from:

U.S. Department of Energy

Office of Scientific and Technical Information

P.O. Box 62

Oak Ridge, TN 37831-0062

phone: 865.576.8401

fax: 865.576.5728

email: mailto:reports@adonis.osti.gov

Available for sale to the public, in paper, from:

U.S. Department of Commerce

National Technical Information Service

5285 Port Royal Road

Springfield, VA 22161

phone: 800.553.6847

fax: 703.605.6900

email: orders@ntis.fedworld.gov

online ordering: http://www.ntis.gov/help/ordermethods.aspx

Cover Photos: (left to right) photo by Pat Corkery, NREL 16416, photo from SunEdison, NREL 17423, photo by Pat Corkery, NREL 

16560, photo by Dennis Schroeder, NREL 17613, photo by Dean Armstrong, NREL 17436, photo by Pat Corkery, NREL 17721.

Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.
1

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Cooperative Research and Development Final Report

In accordance with Requirements set forth in Article XI.A(3) of the CRADA document, this document is 

the final CRADA report, including a list of Subject Inventions, to be forwarded to the Office of Science 

and Technical Information as part of the commitment to the public to demonstrate results of federally 

funded research.

CRADA Number: CRD-09-352

CRADA Title: Vindicator Lidar Assessment for Wind Turbine Feed-Forward Control Applications

Parties to the Agreement: Catch the Wind, Inc.

Joint Work Statement Funding Table Showing DOE Commitment:

Estimated Costs NREL Shared Resources

Year 1 $ 100,000.00

Year 2 $ 130,000.00

Year 3 $ 150,000.00

TOTALS $ 380,000.00

Abstract of CRADA Work:

Collaborative development and testing of feed-forward and other advanced wind turbine controls using a 

laser wind sensor.

Summary of Research Results:

Researchers at the National Renewable Energy Laboratory (NREL) are designing, implementing, and 

testing advanced feed-forward controls for multi-megawatt wind turbines that will help reduce the cost of 

wind energy. Past wind turbine controllers have depended on turbine feedback measurements to 

determine the controller pitch commands. In this setup, wind speed disturbances can only be corrected 

after their effects have been detected in the turbine’s loads and dynamic response, which causes a delayed 

control response due to turbine and pitch actuator dynamics. Light Detection and Ranging (LIDAR) 

systems can provide an advanced wind-speed measuring sensor that provides information regarding the 

approaching wind field to the controller in advance, thereby increasing the controller’s available reaction 

time and allowing pitch actuation to occur in advance to mitigate wind disturbance effects. Feed-forward 

control algorithms that use these “look ahead” wind speed measurements can improve load mitigation and 

controller performance compared to feedback only controllers.

The objectives of the work in this CRADA were to assess a particular commercial LIDAR; the Catch the 

Wind “Vindicator” LIDAR system for providing wind information ahead of the turbine for use in 

advanced feed-forward control algorithms. In this activity, the Catch the Wind Vindicator LIDAR unit 

was mounted to the nacelle of the 3-bladed Controls Advanced Research Turbine (CART3) located at the 

National Wind Technology Center near Golden, Colorado. Data from this unit was collected during 

turbine operation and compared to anemometer data collected on the upwind meteorological tower. After 
2

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

assessing the accuracy and potential of this LIDAR for use in advanced feed-forward control algorithms, 

a preliminary feed-forward control algorithm was implemented in the CART3 software and field testing 

was initiated. The LIDAR data stream was integrated into the CART3 data system so that online 

measured wind-speed data could be fed directly to the control algorithm. Field testing over a several 

month period showed that inclusion of the LIDAR measurement into the control system led to further 

rejection of the wind-speed disturbance at low frequencies compared to feedback alone. In addition, this 

advanced wind-speed information improved the controller’s ability to mitigate critical fatigue loads, a key 

step in reducing wind turbine cost of energy.

These field tests provided confidence that this LIDAR technology could be used to obtain load reductions 

using feed-forward controls that use the LIDAR wind-speed measurements ahead of the turbine to 

improve performance.

Subject Inventions Listing: N/A

Report Date: 11/18/2013

Responsible Technical Contact at Alliance/NREL: Dr. Alan Wright (303-384-6928)

This document contains NO confidential, protectable, or proprietary information.